An ultrasound diagnosis apparatus for obtaining a tomographic image of a subject by transmitting an ultrasound to the subject and receiving the reflected ultrasound has been mainly used in a medical field. An ultrasound probe is connected to the ultrasound diagnosis apparatus via a connector and cable and converts an electric signal from the electric signal body into an ultrasound. The ultrasound probe Transmits the ultrasound probe to the subject as contacting with the subject, receives the ultrasound signal reflected from the subject, and converts it into the electric signal.
An acoustic element of the ultrasound probe is formed of a piezoelectric element and, for example, an acoustic matching layer, an acoustic lens, and a backing material and converts the electric signal and the ultrasound signal. The acoustic element of the ultrasound probe and the ultrasound diagnosis apparatus are connected via the cable or the connector. In recent years, in order to realize a three-dimensional display using a matrix array element, it is necessary for the acoustic element to transmit/receive significantly larger number of signals than before. It is necessary to provide cable of, for example, several thousands to transmit/receive these large number of signals between the ultrasound probe and ultrasound diagnosis apparatus via the cables. In this case, it is possible that a thicker cable reduce its usability and the cost of the cable or connector increases. In a matrix ultrasound probe which has been practically used, a subbeam former circuit is arranged in the ultrasound probe not in the ultrasound probe. Accordingly, the number of cables or connecters for transmitting/receiving the signals is reduced. Also, in order to improve a performance of the ultrasound probe, an amplifier or a switching circuit may be arranged in a place closer to the acoustic element of the ultrasound probe.
On the other hand, the temperature of a contact part with the subject or a contact part with an operator in the ultrasound probe is easily increased by heat generation caused by a power applied to the acoustic element of the ultrasound probe and heat generation caused by a circuit unit arranged near the acoustic element. Therefore, the temperatures of these contact parts are regulated from the perspective of security. As described above, when a circuit is mounted in the ultrasound probe, a problem occurs that the temperature of the acoustic element of the ultrasound probe or a housing is increased by the heat generation caused by power consumption of the circuit mounted in the ultrasound probe.
For example, an ultrasound probe disclosed in Patent Literature 1 has been proposed. In the ultrasound probe described in Patent Literature 1, a case 100 contains a circuit board 101 as illustrated in FIG. 22. The circuit board 101 is connected to a heat transfer plate 102 formed of a material having a high heat transfer coefficient. The heat transfer plate 102 and a shield case 103 are connected to a metal member 105 for an electromagnetic shield for covering around a cable 104 which transmits/receives the signal. The circuit board 101 has a heat spreader (not shown) for transmitting and dispersing the heat and is connected to the heat transfer plate 102. With this structure, the heat generated in the circuit board 101 is radiated. Also, in the ultrasound probe in Patent Literature 1, the shield case 103 connected to an acoustic element 106 and the heat transfer plate 102 contained in the case 100 is connected to the metal member 105 for the electromagnetic shield, and a gap between the circuit board 101 and the shield case 103 is covered with a rigid urethane foam having a high heat insulating performance. With this structure, the heat of the circuit board 101 is prevented from being transferred to the acoustic element 106.